I have a SharePoint 2010 application that is extended for external users to use claims based authentication, now the requirement is that the users should be able to use a trusted social log in accounts Google or MSN IDs to gain access to the site. This is possible using ADFS, but i have little idea on how i can add Google and others as trusted identity provider in ADFS.

Thanks! I had explored on this too... But this method will incur the cost of subscription and also nominal fee to be paid for transactions. I would make this as my last option. I want to know if I can configure ADFS to do the same thing without ACS, also look at its pros and cons, doesnt matter if its time consuming!
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ShankarFeb 10 '12 at 9:44

Danny Jessee has a blog post that shows how he integrated LinkedIn as an authentication source without using ACS. Reviewing how he did that might be useful for you. It builds on the Travis Neilsen blog article mentioned above.